Lots of wineries still ferment their white wines in barrel. The actual process of barrel-fermentation doesn't really vary that much from fermenting in any other vessel. The main concern regarding barrel-fermentation is the fact that if the barrel has not been kept clean and sanitized in between uses it provides a perfect breeding ground for a host of spoilage organisms, such as bacteria and mold and once it gets infected with something it is virtually impossible to get it clean again. Barrels should be stored with a potassium metabisulphite solution in them in between uses. Also, the whole point of fermenting or aging wine in barrel is to impart wood flavours/aromas to the wine and to soften and integrate the wine due to microoxygenation through the pores of the wood. So,if the barrel has been used for more than a few years it will no longer have any ability to impart any flavours/aromas. In addition, most kit wines don't have the hard tannins that need softening through extended barrel aging, so I really don't see much benefit in using a barrel for your purposes. (Other than the fact that it's kinda cool!)