Need advice on TT frame for petite female

What are you petite gals doing for TT frames? I would like to get a dedicated TT bike, but I'm not certain what my options are at 5'3". Right now my main race bike is the Specialized Ruby Pro which I have in a 48cm frame size. The top tube length is about 50.6 measured horizontally from center to center. With these dimensions am I going to be stuck with 650cc wheels in a TT machine?

At this point, I'm not looking for a souped-up carbon racing machine like the Cervelos. Although they are ultra-sexy, the price is out of my budget. I'm looking more in the $1200-2000 range. Any suggestions on what bike brands to look at?

hmmm. I know there are some good bikes right around the 2k range. I think Quintana Roo makes a pretty reasonable one.
I ride an xs Quintana Roo Seduza. Probably a bit too pricey, but it fits like a glove. I LOVE that bike!
It's really hard to find a small frame, but they are out there. Of course a traithlon shop or high end bike shop would be the first place to start if possible. I drove two hours to tri sports (www.trisports.com) because I knew the shops in my area would not have a small enough frame. And I do not buy the "we can tweak it to make it fit you" line either!!
Where do you live? Perhaps someone in your area could recomend a good shop.

This is my current race bike which I use in TTs.

I am 5'10" and have the small frame. I have long legs and a shorter back, I am told.

I will be getting a road race bike at some point, just for road racing (maybe an EMC) - but I want to keep this Giant and make it TT specific... put bar end shifters on the aero bars - not gonna change the actual aeros at all because the whole set up is so comfortable to me.

I suggest you get hold of one of these to try out in an xtra-small, or the most current model (the Aero 2 is a 2004 or 2005 model). It cost us $NZ1200 new, so well within your price range. I do not want a different bike to TT on, though I will be looking at a disc wheel once my TT times improve a little more.

It looks like I'm pretty similar to you, but one size smaller :p.
My race bike is a Ruby Pro too!- in a 44cm.

I recently aquired a TT bike used through Craigs List. It's a Quintana Roo 48cm frame. It does have 650c wheels - at my size (I'm 5' even with longer legs than arms so I need very short top tubes) the head tube can't be short enough on a TT bike to get any drop at all with 700c wheels and no drop = no good aero position. I was lucky and suprised to find that the 48 cm Quintana Roo actually has a short tt than my road bike. It's about as good a fit as I think a little person can find.

As you probably know the Ruby has 700c wheels in all frame sizes and for my road bike I really wanted to keep it that way. 650c's are just so much more of a worry for road racing, but I figure with a TT bike if you get a flat it really doesn't matter cause its all over wheel change or no wheel change. I haven't noticed any handling differences or problems and I'm thinking that another advantage to 650's on a TT bike is that I'll be able to get some nice wheels - disk, tri-spoke, deep section, pretty cheap. Lots of guys got bikes with 650's for Tri's and have now decided that they'd prefer bigger wheeled bikes so there are some good deals to be had out there.

Good luck with your search!

I purchased a cervelo dual (48cm) this season for triathlon. I am 5'3 with a short torso and this fits me extremely well. Cost was about $1800.00. The wheels are 650's which I also run on my road bike. Most triathlon bikes this size come with 650 wheels. I always carry the appropriate tubes and if traveling will take a folding tire. It's never been a problem.