In a car with all your mods, I wouldn't use anything less than Royal Purple, Red-line!!! EVER!!!
Want to burn/blow by less oil, use 30wt. And since you are changing often, 5-30 in the winter. Otherwise, what you describe is not at all unusual for a forced induction motor with mods like yours. It may be on the low side actually!
Most really wide viscosity oils are crap from what I have read. Trying to do too much in one fluid. 25-30 spread max!
If you really want bearing/startup protection, throw some break in additive in there which has all the good anti-galling stuff in it the EPA/API has made them take out of newer oils to keep the O2 sensors happy longer.
And if you want to learn more about oil, start at
Bob The Oil Guys
Purolators are at Pep Boys and occasionally on sale.
Oil threads:
There is a scan of an article in this one that is semi-useful, but some weights they used were odd and engines don't really have wear points like that.
http://www.seccs.org/forums/showthread.php?p=105842
http://www.seccs.org/forums/showthread.php?p=144930
Any thread with OIL and Royal purple and Red Line is probably worth a scan.
Filter info from one of those threads
http://www.iwsti.com/forums/2-5-lite...ions-pics.html