Yes, you can.

As stated in the spell Gaseous Form:

The creature is subject to the effects of wind, and it can’t enter water or other liquid.

Emphasis Mine, size doesn't matter in a gaseous form, as you will be subject to the effects of wind as any other gas would be

In addition to the effects noted, a gust of wind can do anything that a sudden blast of wind would be expected to do. It can create a stinging spray of sand or dust, fan a large fire, overturn delicate awnings or hangings, heel over a small boat, and blow gases or vapors to the edge of its range.

With Rules as Written, you can definitely cast Gust of Wind as a standard action, then using your move action to move into the gust, to carry you along.

If I was GM though, I would rule against this use, as the spell to me seems intended that a single blast of wind comes from the caster, moving away. The actual ability of the caster to get caught in the gust seems very ambiguous. It's your game though, and if you feel that the Vampire would be best served as a storyline villain, and not just a once off, that's something to discuss with the table. Just make sure you don't have anyone ready to snipe him off after the 60 ft. that he moves.

The rules don't specify any bonuses for moving at those speeds in combat, or using Wind Walk at all in combat. It wouldn't be unreasonable for a GM to give you an AC bonus for being so hard to hit, however.

The real problem with using Wind Walk in combat is this section from Gaseous Form:

It can't attack or cast spells with verbal, somatic, material, or focus components while in gaseous form. This does not rule out the use of certain spells that the subject may have prepared using the feats Silent Spell, Still Spell, and Eschew Materials. The subject also loses supernatural abilities while in gaseous form.

and this from Wind Walk:

A wind walker can regain its physical form as desired and later resume the cloud form. Each change to and from vaporous form takes 5 rounds.

Wind Walk prevents you from performing most offensive actions, and it takes five entire rounds to leave vaporous form. Many combats last less than five rounds to start with. Wind Walk is designed to exclude combat and really only be useful for travel.