So...I have this stunter that was built for the PA .65...had a .75 in it too...but I don't have the
powertrain and Randy is out of stock for the forseeable future on them...and I am thinking...$600
for that or...an electric conversion that would probably cost less or if nothing else the same and I
would have several batteries for it.   I have read the current set-ups listed here but technology
changes all the time.   With the PA setup the plane weighs 70 ounces....What do you guys think?

What are the options?

If you copy Pauls setup, you would want to use his first setup, not the current one. The current one is streamlined for a smaller lower drag airframe and wing.

David:
Lots of big power choices out there, I have no quibbles with what others have already said here - just offering up one more variation.  We have been flying flying an 80 oz Strega with LOTS of power.  It uses a 6 cell pack to help keep the current draw lower and reduce the HEAT.  It can also use packs that are physically small.  Kenny Stevens recently converted an old PA-65 powered SV to the same power system and is very happy with it:

Arrowind 3526 Motor (Brodak BH-1841) http://www.brodak.com/shop_productdetail.php?ProductID=8844

Battery: depending on "dragginess" & final weight, 62x2200 mah or 6Sx2800 mah.  We have been flying the Strega on 2800's but believe we could use the 2200's, especially if it had a thinner wing or a little less weight.  THe 2200 pack saves 3 oz versus the 2800's: http://www.brodak.com/shop_productdetail.php?ProductID=8999 or  http://www.brodak.com/shop_productdetail.php?ProductID=8849 

ESC: Castle Phoenix 45 or Ice 50 Lite, in "Set RPM" mode

Timer: Hubin FM-2SR (Brodak BH-1870)  http://www.brodak.com/shop_productdetail.php?ProductID=8860

Prop: APC 13x4.5EP (electric series pusher prop) turning about 9800-10,000 RPM


The biggest problem with CONVERTING an existing airframe is that it will likely gain a couple ounces - though compared to the old "gassie" with a full tank of fuel the weight differences get pretty small.  Building from scratch will let you make up any penalty...