Wheels are probably going to be the most important part in your build so some of those 36 holes as previously suggested would do great and if you want even more bomb proof you can go with 48 hole rims and hubs. You will also want to be as comfortable as possible so go with a steel frame and don't cheap out on the saddle. Last thing, and probably most beneficial, would be to ask this question on the Clydesdale forum because many other people are in your predicament so don't feel abnormal haha. Good luck!

PS my uncle weighs about 235 and he just bought a Fuji track; he loves it so far