I would have to agree with both Lee & Underclocked both have some great advice BUT again I AM A KNIGHT GUY Big time , although I do not like the QLA System I have to admit I have been reading some Awsome reports on the Tryumph with BH 209 and some awsome accuracy to boot. So if I was you I would find a place that has both rifles in stock and go handle both to see witch fits you better also you may want to look at a Knight Disc Extreme and the TCpro hunter but I will say eather TC or Knight you can't go wrong ! Bullets to look at would be TC Shock waves - Hornady SST - Barns Bullets - Parker and I shoot a 300gr Sierra .429.5 in my Disc Extreme MH and it is cheep and is super accurate , as far as Powders if you don't like cleaning your gun much look at the new BH 209 but if you can't find it locally it will cost you a pritty penny with the hazzard fees and so on I am dieing to try it but untill I can get it local I will not pay close to $60 for 10oz but if you don't mind cleaning your gun most deffanetly loose 777 is the ticket IMO. and if you want to stock up on 777 at the end of the year Wal-Mart will run it for as low as $10 per 16oz this is when I stock up on my 777 .
As far as your powder load IMO there is no reason to try to shoot more than 100gr to 110gr of powder you will find your best accuracy between 80gr & 110gr of loose powder. I very very seldom shoot more than 100gr .
I would actually pick my gun before I got a scope FOR THIS REASON if you choose a liter gun I would go with a scope with a little more eye relife 3.9" to 4.5" don't need Scope Eye , A heaveyer gun 3" to 4" will do fine.

But what ever you choose Keep us posted on how it does .

Ron