I'd certainly do a header and tune before the cams. Regardless is you like Tom or not, he does provide free NA upgrade tunes so once you do the cams you can have him retune it.
As far as doing the cams though, aftermarket gears aren't required, but can be beneficial to get the most out of the camshafts. You should also consider aftermarket valve springs if you are going to be revving high. Also you will need a set of feeler gauges to measure the clearance between the cam lobes and buckets and if any are out of spec with the new cams, the bucket will need to be replaced with one of the correct thickness.
Of course this last part people often skip. Often works out ok but if it were my car i'd want to know for sure it was done correctly.