? HELOC or REFI or BOTH??

If your going to refinance...is it also a good idea to try and get a HELOC? My wife and I currently do not have a HELOC.....but want one so we can make some improvments to the home. We are responsible savers and spenders. How do HELOC work.......can we get a fixed rate for the life of the line?...or does it adjust? Also....If we reifi....can we name the lenght of the payback. for example....we have aprox 22 years left on our loan.....when we refi...can we ask for a 22 year pay back...or does it have to be a 30 year payback.....basicaly we just want to lower our rate without affecting how long the loan will be for. We currently have a locked 6.5 rate for the life of the loan. Please advise. The HELOC just seems like its a good option....b/c it allows you to improve and draw at your own pace. We live on one of the more stable housing markets (as stable as stable can be in these times).....Syracuse NY.

Also....If we reifi....can we name the lenght of the payback. for example....we have aprox 22 years left on our loan.....when we refi...can we ask for a 22 year pay back...or does it have to be a 30 year payback.....basicaly we just want to lower our rate without affecting how long the loan will be for. We currently have a locked 6.5 rate for the life of the loan. Please advise.
Odd. I was coming here just now to ask the same question. We are currently 7 years into a 30-yr, at 6.5% and were thinking of a refi to at least a point lower (hopefully 5.15-5.30%).

As I thought:

http://www.lsoi.org/lsoi/Information/pamphlets2/housing/refinance_mortgage.pdf