need to know what the best vietnam UH-1D Huey is?

If you want to use Dragon's 1/35 Helo Crew figures, the only UH-1D/H (longbody) Huey to use them on is the Dragon UH-1D/H kit (or the earlier Panda boxing of the same plastic).  It is the only one in 1/35 and has some issues.  You could also use the 1/32 Revell UH-1D/H, but it has its issues as well.

For bullet holes, thin the area you want the hole in from the back side with a dremel tool and a grinding bit.  Go slow so you don't melt the plastic.  When you have it paper thin, use an xacto knife to poke a bullet hole in it from the front side.

Hope that helps.

The DML crew you want to use is in 1/35 scale, which helps to narrow things down. The only -D model Hueys available in that scale are from DML, although I suspect that the old Panda kits can still be found. Doesn't really matter there, because it's the same kit.

DML re-popped the Panda kit, but more recent releases (kit  3538)  have included a fret of photo-etch that really dresses things up. Plenty of aftermarket support is there to help detail things up.

The next closest in scale is the venerable old Revell-Monogram -D in 1/32. It needs a little elbow grease to bring it up to modern standards, but the DML crew works fine inside of it, even if they are just a tad smaller in scale.

Edit- looks like Gino beat me to it while I was tapping keys! :)

thanks for the suggestions, I heard the crew is close to impossible to find, so maybe a different scale will help

The best Huey kit in ANY scale is Kitty Hawk's 1/48 kit hands down.

If you still want to go with a larger, 1/35 Huey, Academy's UH-1C gunship models are excellent and they include a 4-man crew.  They have a few different versions with different armament combos and decal options.

Included crewmen.

If you are willing to spend a little more money, another option is resin crewmen.   Bravo 6 does an excellent set of pilots... 

...and doorgunners (which also includes the M23 gunmounts and M60Ds).