Let's see, HMers...

You'll probably want:

Cut
Fly
Surf
Strength
Defog
Rock Smash
Waterfall
Rock Climb
Flash
Dig

You have on your team already:

Surf

That's nine moves left, so a minimum of three HMers. I recommend:

TURTWIG (Select from Prof. Rowan's Briefcase in Platinum)
Cut
Strength
Rock Smash
Rock Climb

STARLY (Catch in Route 201 or 202 in Platinum)
Fly
Defog
whatever (TM 46: Thief is an interesting option)
whatever

PSYDUCK (Catch in Oreburgh Gate basement after beating Roark)
Waterfall
Dig
Flash
whatever


...I might be able to reduce this to only two if you pick at least one of the moves I've listed that you don't want access to.