Need serious and personal advice on putting my 2 overweight cats on a diet...

I have two cats and they both need to lose some weight, but I'm not sure how
to go about it. We're currently suffering financial problems so I can't
really afford to take them to the vet just for diet advice, at least for a
few months.

Luna is a 4 year old male and is a Maine Coon/tabby mix. He's the one I'm
worried about the most. He's a very large and muscular cat, but in the past
few months I have increasingly noticed that he is having problems with his
weight. He can't jump as well as he used to, he has no stamina for playing
(won't even chase his sister all the way down the hall anymore), and his
grooming has suffered (particularly on his back). He is the dominant cat in
the household and I have noticed over the years that he is an emotional
eater. If he feels less dominant or threatened or depressed, he will go and
eat even if he just ate a short time ago. If one of us walks into the
kitchen where his food is, he'll go eat. He needs to lose at least 2-3
pounds, maybe more (I need to get him on the scale).

Mina is a 3 year old female and is a Siamese/tabby mix. She doesn't need to
lose much weight at all (maybe a pound). She is very skittish and not at
all dominant. I think that her weight problem is simply from inactivity,
since she doesn't eat much.

They've both been allowed to have all the dry food they've desired most of
their lives, since that's how my husband's family always did it. I only had
one outside cat, so I went by his advice. We also both used to work second
shift, and they didn't ever really adapt to waking and eating on our
schedule, so not having a hungry cat meowing in my ear at 5am worked at the
time. Now, I'm willing to endure more inconvenience to get my old playful
kitties back.

Luna and Mina have been overweight for about a year but I've only been able
to convince my husband that we need to do something about it now. One
reason I've waited is I'm not sure how to go about it. Now I'm upset that
I've waited this long because our first baby is due in 9 weeks and I don't
want to spring too much stress on our cats at once. They've just been
banned from the bedroom due to both the baby (we're cosleeping and I'm
worried about it, long story, decision already made and I'm not backing out
of it) and my husband's allergies (which have improved immensely in the
couple of weeks they haven't been allowed in) and Luna isn't dealing with it
at all well (usually pounds/cries at the door once or twice a night).

I've pondered starting out with mixing half regular and half-diet until
they're out of the regular food and then substituting diet food into their
feeder for a while and see how that works (will Luna just eat more of it?).
We've started instituting play periods every night with a laser pointer
(we're currently trying to find a AA or AAA battery model since the tiny
batteries are expensive) and other toys to help them become more active. Is
this a good transition idea or should I go straight for rationed eating?

When we do portion control, I've already figured out that they're going to
need separate bowls. With treats, catnip, and everything else, Luna will
eat his first and then go after Mina's. She's a slower and pickier eater
and will always defer to him at the food bowl (not to mention he seriously
outweighs her). Will this persist or will she get more of a backbone if
she's hungry and he's going after her food every day? How far do I need to
go to separate the bowls? Are we going to need to supervise?

What diet food should I feed them? I love Eukanuba, but we simply can't
afford it at the moment. We've been feeding them a brand from Sam's Club
(Exceed I think its called) that had a similar formulation to Eukanuba. I
didn't notice any diet food at Sam's so I'll have to go to Wal-Mart or Petco
(no local Petsmart). They've never been overly picky so I don't think the
change in food will bother either of them. I want something of good
quality, but I don't know what to look for and I can't afford the premium
brands (although if its rationed, premium food might be more reasonable down
the road but not for the first few months).

Next, what portions should I feed them? Luna is over 25 lbs (but he is a
massive cat by nature), so will he need a little more than Mina (normal
sized cat)? Are there any portion guidelines? How often should I feed
them - morning and night? When they were kittens, they were fed three times
a day, but we're not always home. And what should we do if we're going to
be gone? Occasionally we're gone on overnight or weekend trips and we don't
really have anyone who can come over and feed them. Are they going to be
pounding at the door at 5am wanting food or can we train them to our
schedule?

Any suggestions would be more than welcome. I'm worried about my cats'
health and I want to get them back on track. I'm googling for website
advice, but any personal experiences would probably be more helpful. And am
I just hormonal or will all these changes (no bedroom, diet, and new baby)
going to be too much for them to deal with at one time?

- Joanne