Plan for a mill...
Even though I've got a decent 20" drill press I find myself using my small bench top vertical mill more often when hole size and placement needs to be accurate in metal. If I had it to do over again I'd have spent less on the drill press and spent the money on a bench top mill like a Rong Fu RF-45 knock-off or an older Bridgeport.
If you're going to do projects like sidecar mounts that actually fit snugly without deforming frame tubes you'll quickly come to the conclusion that a mill (and a lathe) are indispensable. It all depends on how much of a shop geek you want to be.
Right now I'm helping a friend get some bicycle tooling orders out the door and I'm using his Bridgeport, and all I can think about is how I can get one into my 1 stall garage and still have room for the wife's Miata.
And the welder? I need to do thin stuff as well as 1/4" mild steel, plus aluminum and stainless, so I settled on a ThermalArc 185 TIG. Possibly overkill but this tool buying and using stuff can get to be a disease.
"They're smarter than you son... that's why they're the police."