I used to mess around with SU carbs quite a bit. They are simple and work well if you take the time to make a proper initial set up.The 2 inch carbs from a Jag are kinda expensive new or used.The 1-3/4 inch models were used as an upgrade on MG's and I believe on Healy 6's,can be easier to get for reasonable money.
Another sidedraft option is S&S carbs as used on Harleys.You can pick them up at swap meets for 50 bucks each.