Mesa Boogies come from the factory with Groove Tubes installed. They're good tubes, just not quite as magical as Aspen Pitman would have you believe. My own experience is that there is not much value in matching tubes beyond ensuring that they will all bias correctly at the same voltage. There are some audible variations in sound quality between diferent tube types, so changing your 6550's for 6L6GC's (or vice-versa) may be of interest to you. The main point in selecting good quality tubes is knowing who actually made them. Some tubes are better made in different countries/factories than others. You can google search for websites that offer opinions on who makes the best tubes of the type you want. Be prepared to sort out the truth from the hype. But then, any web research involves that.

Good Luck.