Hey, you sound a lot like me! Twohand is right that you'll rarely, if ever, need a really high end bowling ball. I use pretty exclusively low end or fairly old equipment on every condition I've ever played, and I know I'd never be able to control the top end monsters with my low ball speed (I've tried a couple times and it was UGLY). I do think you may need something dull (eventually), depending on the volume of oil you plan on bowling on. Even on a THS if it's heavy, I sometimes go down as far as 500 (but I sand my own stuff, so it's not a big deal). I think as far as core type, you're probably better off with a symmetrical ball.
If you're not bowling on heavy oil, I'd recommend a Brunswick Slingshot drilled strong. I think it would fit your game rather nicely.
Nice to meet someone who has similar style!
I thought of the Slingshot, and also am considering the Grape Vibe by Hammer. I wonder if the Vibe would cut hard if drilled aggressively?
ad.