Sole Trader / Partnership.

If only one of you is really running the show, and will own the business alone, while employing the other, then it will be sole trader, otherwise partnership.

If you are supplying leather to cobblers, it could be both.

There is nothing to prevent you from starting as a sole trader (and employ your wife) - or vice versa - and then convert to a partnership at a later date. This would be quite a common scenario if profits are likely to be low in the early years.