I'd plan to change springs. Pretty much any modern cam of the sizes being tossed around (except the MP .528) will need more spring pressure than the factory RPM springs. There's a reason there are always sets of those for sale.
I'd 3rd or 4th the 275HL. It's not a lot of coin and will work well with what you have - except the valve springs. Keep the static ratio below 10:1 and the quench less than .035" and you'll be stylin'.

Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.