I would recommend you stick with separates but your budget could be a problem. Used Modwright, Belles, DeHavilland or Van Alstine are all quality but may be too expensive. If you are not averse to Hong Kong designed and built I had an Audio Experience Symphonies tube pre which performed well before I upgraded to a Van Alstine. With tubes rolled to NOS RCAs there was not a great difference between the two preamps and the Audio Experience could probably be found for $600 or less.
