Lovepedal Kanji Overdrive, it's amazing, it's a tube screamer on steroids, that's my fave, I've owned Fulltone Fulldrive 2, MXR OD, Tube Screamer, and for the money(it's cheaper than Maxon) it is amazing.
There's gotta be a place in Cape Town or Joburg where you can get the guitar you're looking for, otherwise, yeah just buy one and have it shipped dude!
I work a lot with pedals, and how you set them up in the chain vs the loop will affect your sound, purely for playing death/black/grind type metal I would use something like an MXR Fullbore Metal pedal for the distortion through the clean channel if the amp isn't giving you that saturated heavy...
I'm giving Curt Mangan a shot, they have a 12 thru 54 I like to use on the 6's tuned down C to C, was using Not Even Slinky EB's and that damn 3rd string drives me crazy.
That is a massive string! I would say have a pro do it if you can, and do a proper set up, and sit behind them, and watch them do it, and learn how, Truss Rod's can be tricky, and typically you only give them a quarter turn at a time, if you crank on them, you can crack the neck, or warp it.
My Dad will always be my hero, he got me my first guitar, a Peavey T-16 for 50 bucks when I was 8 years old, 22 years ago! He was the only person who thought I'd stick with guitar, he's the heat, to quote Will Ferrell from Wedding Crashers "LOVE YOU DAD!!!"
If you have a Floyd style trem a Trem Setter sometimes will eliminate those pitch raise, and lower problems if you have a specific string gauge you prefer.
The 6505 is a cool amp in the lower price range I think, I've also been pretty impressed with the stuff you can do with the Randall XL series, the V2 Specifically for heavy focused metal, it's not all tube but definetly has a heavy sound and the high gain channel definetly had a tube influence...