Rose, you're on a concentrator, right? I would first suggest that you buy a second concentrator, because moving up to a different torch won't gain you much if you don't have the equipment to fuel it's potential, so to speak.
Also, a Minor on one concentrator is nowhere near the heat of a Minor on two concentrators. Your current torch is capable of working boro quite nicely, if it has enough oxygen to crank it up. Once you have that second concentrator, if you decide to upgrade to a Lynx or a Pirhana, then you'll have the ability to utilize their greater firepower. With one concentrator, neither will give you much greater performance than your Minor does now (and I don't think Lynxes perform well at all on one concentrator).