Like Tac says...under 20k, the Mossie is buff hunter extraordinaire, 2 Merlins and 4 Hispanos is one hell of a combo, throw in a quartet of .303 to give your tracer stream a more 'solid' look, and yer cookin with gas.
At altitude, nothing makes me more nervous when Im buff driving than a P47 in the area, 8 .50's make short work of pretty much anything they hit, and the higher you take a Jug, the better it likes it it seems.
Of course, the 262 in the right hands is untouchable, and 4 30s turn buffs into hamburger quicker than you can say ' toejame he's closin fast...cant track him!', but personally I wouldnt risk that many perks on a buff kill.
Blue
Oh yeah...the 109G6 with gondolas works great on buffs too, and is survivable in that it is quite capable of mixing it up with the escorts aswell as hunting the buffs.
Havent tried the 110G much at all yet, but I dare say it would have to rank way up there with the best of the buffbusters too.
BTW, it takes a fraction of the ammo required to destroy a bomber's fuselage to rip off one of it's wingtips, and the chances of bringing home a buff without a wingtip are marginal to say the least, most often they spiral in there and then...the hard part is resisting the urge to shoot at the centre of the target aircraft.