My wife and I have decided we need to make our first deal our own house. The problem is we don't want to tie up our cash so was considering using a mortgage. We both have 0 credit history so was considering an FHA loan.

My main concern is since it's so difficult to find deals right now in Dallas, won't having to use a loan to do the deal make it even more difficult since motivated sellers want cash buyers? If I were to buy with cash and then refinance out with an FHA loan, would that be a good idea? If so, how long would this tie our cash up? Anyone have any advice?

Buying with cash will certainly put you in position of having a stronger offer.  If you're talking about an all cash purchase of the property, you can turn around and finance out of it immediately, since you won't have to worry about seasoning an existing mortgage.

If you do all your prequalifying and preapproval work up front, it shouldn't take more than 30-days to close. The only thing you have to worry about is making sure the house can be underwritten in its current state. FHA has some pretty stringent rules around property condition.