$400 pre-amp/proc or wait awhile

My wife & I have our first two children on the way & of course, a limited budget. As luck would have it, our pre-amp recently broke on us. I have been researching HT and figured I would accumulate components one at a time. I currently have good front (Vandersteen 2ci) & rear speakers (Frieds) and a good 2ch amp (Adcom GFA-555).

Since I need a new pre-amp, it seems like that's the next piece to get, but it also sounds like the technology on these advances much faster than the other components.

Am I better off waiting on the proc & either fixing my current one or buying a used 2ch. pre-amp to tide us over, OR can I find a reasonable proc that won't be outdated by the time I assemble the rest of the system (~2 years)? We have about $400 to spend right now...maybe up to $600 later. I wouldn't want to invest more than $200 in a 2ch pre-amp.

One other question, are both DD & DTS essential? Given my budget I am tempted to get a better quality component without that might lack DTS.

Any thoughts or recommendations on specific pre-amps or processors would be appreciated.
Two children on the way? You need something that can play kid's stuff real good.

to answer your question, I am not so sure that all of the new stuff is going to impact your price range. Most of the change is happening at high end.

I would buy a used preamp for now as, with the upcoming changes in the industry, there are some really good preamps in the Audiogon classifieds that are selling for not all that much. I recently saw a Rotel Receiver that had sold for upwards of $1,000.00 two years ago available $375.00.

Just be sure to subscribe to Audiogon Bluebook. If you buy for less than bluebook, and don't like it or want to upgrade in the near future, you can probably re-sell it for minimal loss.
Most of the changes in receivers are about 6.1,7.1, dts ex, dvd-a, and sacd. One could eaisly find a used receiver that just did DD for movies; for that kind of money.I mean with 2 children on the way,you do need another hobby.(and something that will play loud enough to play-over the crying.)
The Panasonic SA-XR45s digital receiver has caused many heated debates at audio asylum forum, it can be had for around $300 on the internet. If you can beleave what you read on the asylum..many buyers of this cheap digital receiver are selling their megga-buck amps because they report that this little receiver blows them away. I have no experience with digital amps of any brand myself.