Head has been designing and manufacturing excellent ski boots for 32 years and has a large variety of ski boots to offer. Each pair of boots has their own special feature and serve you better for a unique purpose.
You must take your time when looking around and choose the right model from the huge variations of Head ski boots. Try to consult with a professional boot fitter as mentioned, for the exact pair for you. Buying the wrong ones can mean only one thing - disaster. The boot fitters are dedicated in providing customer service and they can guide you towards the best pair.
If you decide to buy the boot, binding and skis all together, make a decision on how much you want to spend on each gear. The best advice for you is to spend the most on the boot itself. If you are a little tight on the budget, then buy the Head ski boots first and then spend the rest on what's left on the list.
A common mistake is buying boots that are too comfortable. That is, buying more spacious boots than really needed. This can be dangerous when you are on the slopes. Generally the elements on the boot become loose after wearing a couple of times, so if you buy too spacious boots, you'll lose control of them. What you should do is buy a pair of tight ones and wear them for 15 minutes. This will allow them to loosen up.
Remember that although all Head Ski Boots come with adjustable cuffs, you should pick the ones that suit your exact needs. Make sure the boots fit according to your foot shape or else it can be damaged by tripping of your feet without you even noticing it.