Its a great speed army and yes Boarding plank (allows one Ork model to attack an enemy Vehicle with in 2") would work better with the theme ur aiming for although the
RPJ gives you the extra 1" b4 all ur boys jump out and mulelr ur oponent

but with
KFF there shoul be no worries just move Unit 1+ur Mke in the middle all trukks being open topped = lots and lots of pain for any one you face as mek is total power house in small games
my 500pts is a shootie army designed to muller tau
HQ - Big Mek -
SAG 95pts
Troops 1 - 10 boyz - Shoota's 60pts
Troops 2 - 10 boyz - Shoota's 60pts
Elites - 5 Lootas - 75pts
Heavy Support - Battle Wagon - 'Ard Case, 2x Rokkit, KillKannon, Kannon,
RPJ(just incase i need to move to target stuff) 200pts
i just like shootie orks
with between 5 - 15 shoots from the lootas and a i rarely only get 5 normally toting out 10-15 most things even with the rubbish
BS of orks get shot to pieces and another 20 shots per troops choice
and the
SAG is the shiznit in 18 games i've only roleld doube 1's once and doubles 5's twice average
Str is around 8-9 with double 6's coming up once or twice every other game maybe im just lucky