Can I use a bloodknot with a level wind reel (Abu Garcia Ambass. 6000 and 7000)?

Hello,

Myself and my buddy hooked into some "big ones" this past weekend. We
never got anything inshore because our lines kept snapping. Most likely
blacktips or spinner sharks is what we where hooking up with. I have a 15'
Ugly stick with a Abu Garcia Ambassedeur 7000 on it and it's filled with
stren 20lb test. I had an 18" wire leader on but obviously that wasn't
good enough. I want to buy some braided line (probably from bass pro) and
then put a shock leader on the end of that. I'll probably get 50lb test
braided line and also 50lb test mono. My question is how much shock leader
and wire leader should I use and most importantly, will I have trouble
casting if a bloodknot hits the levelwind? What other alternatives do I
have (besides removing the levelwind)? Any tips would be both welcome and
appreciated!

Thanks in advance,
T