I'd actually go for a standard vice over the tilting one unless you can forsee a lot of angular work, remember you can tilt the work one way in a standard vice.
Lever type DTI an a small magnetic base so you can set the vice jaws true to the mills x- axis.
Although you have a drill press you may well find the mill better for drilling as you can use it to place holes by co-ordinates which is likely more accurate than marking out and drilling so a drill chuck would be useful.
Some form of edge & centre finder so you can locate the part in the vice or on the table and then know how much to take off.
As Neil has said one of the hold down sets if you don't want to make your own tee nuts, etc. The ER holders can usually be bought with a basic set of 6 collets in teh popular sizes. Avoid sets of unbranded cutters that can look like a good buy as they are often not good quality. A few branded cutters would be better, the FC-3 ones are quite reasonable but also talk to Ketan about cutters he may be able to supply something suitable.
J