In this case, niether the existing septic nor water system will pass muster, so those reasons for building on the developed lot do not apply...
The lots are already legal lots of record, and I would never combine them on paper, but would like to hold on to the "extra" lot forever even if I don't build on it.
I don't know a heck of a lot about money, but the nice lady at the bank told me my credit score is 770, she seemed pleased so I guess that won't hold me back. I have my own business which is good for just about everything accept showing income to Uncle Sugar so the limiting factor for me seems to be ending up with an acceptable debt/income ratio... The FUNNY thing is, since my income would be a little low for the amount I want to borrow, the bank wants to charge me a little higher rate to cover the additional risk.................yep, in other words, to help me out, they'll raise the debt side of my debt/income ratio ! At any rate I was happy to hear that all of the bumps in the road are passable, now I feel more confident about getting picky looking for the best deal...

I appreciate all the replies, and I never thought ony of you guys were trying to make a sale .