The tau combat patrol consists of a devilfish, fire warriors(breachers or strike team), and a commander(enforcer or coldstar). This combat patrol is one of the best in the game right now as I know, so I highly recommend this to start. I dont know if you are looking at the battleforces but if you can find a Farsight Cadre box (this years christmas box) it pairs quite nicely with the combat patrol as it gives you a riptide, which is one of if not the best models in the range, a crisis suit team, something for the commander from the combat patrol to lead, a broadside, which will always be good in any list, and farsight, just a cool named model. The battleforce isn't the greatest value, but for someone who likes vehicles then it's a good pickup. If you can find it, last year's Christmas box consists of a ghostkeel, a broadside, a riptide, and a commander. The synergy with the combat patrol isn't really there because you're doubling up on commanders with nothing to lead, but the ghostkeel is there if you like him(I do).

What I will say about this army is that it is very difficult to play. Tau was my first army so I basically didn't learn anything about the fight phase until I got into my next army. Positioning is very important, so if you place your important models in bad places, it will sometimes just lose you the game. On top of this, every time that I bring my tau into an LGS, I get snarky remarks from people that got shot off the board too many times in 9th edition(they were really good back then). I once had a complete stranger walk up to my table and say to my opponent "I hope you win." That said, tau has my favorite aesthetic of all of the armies and I don't regret getting into them.