BMX - Cruiser question, or go 20"?

Okay, I'm looking at geting into BMX for the first time at age 38-5'6", 150lb. I thought I'd narrowed my search down to an SE Floval Flyer (24") or a GT Power series 24" . I've done some mountain biking, so the 24" felt pretty good, and I understand that's what most guys my age are riding. But I know I'd get used to a 20" eventually.

So my question is this: Should I get either of the two bikes above, or go for the 20"?
Bikes to consider:

SE Floval Flyer 24"
GT Power Series 24"
GT Power series pro 20"
SE PK ripper

The reason I'm looking at these is that I can get them at a pretty good discount.

The ones you have listed are race bikes so presumably the intent is to do some racing. I would suggest going out to your local track(s) and see what the guys in your age bracket are racing and go down that path. The rationale for my suggestion is that it is loads more fun to be in with a bunch of guys that are in your age group than to be thrown in with a bunch of 17 year old Expert level riders because you are the only 30+ guy on a 20 inch bike. Different tracks seem to have a different make up, the track I started on all the older guys race cruiser but one of the other local tracks it is split 50/50 with a few guys racing both.

I have never ridden a GT but tried a used Floval 24 last year and liked it a lot, it was a very stable feeling bike. However, I am a foot taller than you and outweigh you by 80lbs so my opinion should not be what you base your purchase on.

Yeah, I did some checking around and found that there are a lot more classes with guys my age on the cruisers than on 20" bikes, wich feel really twitchy to me now. So I am going to stick with the cruiser class, at least to to start anyway.

I know SE is now part of Fuji, and the old ones used to be pretty good, but haven't heard much about the new ones. The Flyer specs out about the same as the GT, and costs a little less.

Awww, come on. Go with the 20". But either one of those cruisers are solid bikes anyhow. The new SE bikes are pretty sick looking too.

Like Andymac said, I'll be racing more with guys who are my age on cruisers, and let's face it: I'll look bad enough without getting stomped by 17 year olds!

I'm looking at this as an entrance into the sport, and more from the aspect of having fun. I'm old for a rookie, and I am wanting to do this with my kids (6, 8 and 10), and as a hobby/way to keep in shape. But I am a bit competitive, and I'll be too frustrated if I'm starting out in a class where I can't be competitive. At least if I'm getting beat by other guys, we'll all be old enough to go out for beers and laugh about it afterwards!

But, if I do get where I want to be, 20" would be the next step.

I'm looking at this as an entrance into the sport, and more from the aspect of having fun. I'm old for a rookie, and I am wanting to do this with my kids (6, 8 and 10), and as a hobby/way to keep in shape. But I am a bit competitive, and I'll be too frustrated if I'm starting out in a class where I can't be competitive. I tried to get my two sons into it about 10 years ago when they were about 7 & 11. Sadly they had no interest. Looking back I should have jumped in anyway :)

There's a UK company building cro-mo 22" wheeled bikes. Theres a pic on Andy Preston's Blog. From what I've read on other forums it's not Toys R Us junk - it looks like its got decent geom and the tyres are high-pressure - I'll wait til one shows up in the local shop and then post a pic.