If your looking for low / mid range and you want to go to gear drive over tensioners I would suggest looking at the woods cam or the andrews cam. If you stay with a 240 duration and 500 lift your going to see the lower end results.
The Woods tw6g cam is very similiar to the 211 cam from harley coming on at approx 3500 rpm .
the tw6hg is most like the SE 251 if your looking for comparisions. I know they are not exact, but to give you an idea of what they are like. This one comes on early and runs till about 4600 than starts to break down
I had the 251 in ultra that i had brought up to a 103 with a stroker and with some head work it was at 109 / 117 at 10.3 to 1.
Andrews has very similiar gears as well
http://www.andrews-products.com/motorcycle/cams/twin_88_GEAR_DRIVE.htmI would take a look at the 59g it will leave you at 10:1 and will run from 2400 rpm up.
Honestly if your going to change the Cam you might look at doing a small amount of porting on your heads and opening up the intake opening as well as putting in compression releases changing the springs etc it will allow you to take more advantage to the cams out there without spending a huge amount more. You can get the heads done for around 600.00. Woods even has compression releases that match pretty closely to our motor colors. (just a thought)