> A good microscope for soldering and inspection (could be an USB microscope) for around $300
You want an USB microscope to look and measure really small stuff (the Adaftruit one is fine), but for general lab work, you want stereo vision. A Mantis is great (I used to work with one), but unless you work hours a day with one, it is an overkill, IMO. In my lab I now have C2-D microscope from GX Optical (in US, they are called GT Vision):
http://www.gxoptical.com/html/gxm_stereo_microscopes.html#c2d). I have the optional 0.5x lens (to get 5x mag., 10x is too much), and I'm happy with it. I don't solder every day, but I do all SMD work under it. Plan to upgrade the lights, though.
> A reflow oven for stencil soldering (from $500 to $1200)
You don't need to spend that much, the pizza oven route is good. Mike says you don't need a controller, but imo, the 129€ I paid for one is well worth it. You gain a true controlled soldering profile (which is nice for the peace of mind, if not anything else) and ease of operation, just press a button.
> Could someone share their experience with the MSO's?
Compared to a logic analyzer? You want both. A MSO is good for insight and responsiveness. With a fast real time view you'll see issues like "that doesn't look stable", "it was there for a while but went away", "activity here seems to affect something there", that an analyzer does not tell you. A logic analyzer is a much better analyzer and gives a much deeper look to the actual logic of the system. I have an Agilent MSO and a ZeroPlus, and while there is some area where they overlap, on both ends (hw vs sw) there are tasks where one tells the story but the other would not.
> What type of designs would require a 350Mhz oscilloscope?
Anything digital, really. It is not about the clock rate of your system, it is about the speed of the transitions. You want to see the cleanness of your signals, and modern ICs are fast. i have a 350MHz scope, and it is slow for microprocessor/DSP hardware work.
To add to the list:
*A license for Altium.
*Spend as much money as you can to the specific instrument on the area that you plan to work on. If you work on audio, look at Audio Precision stuff. If you work on RF, get the best RF tools you can afford etc.
*As said, some spare money for stuff that you didn't think of and stuff that comes to market next month.
*Really good lights
*ESD protection (bench and floor mats, ESD storage cabinets etc)
*endless supply of prototyping stuff: plain boards, modules, general parts, connectors, wires etc. You mentioned PICs. There will be numerous situations like "It would be handy if I could hook up some buttons / a serial terminal and a processor to these lines and have it to do X on command". You want to be able to go to your lab, take a PIC module, put it on a veroboard and solder some connectors to it. Then you take your standard software template for that board, drop some code and off you go. You don't want to start ordering stuff at that point! (I'm a fan of serial terminal debug: I can take a board, interrupt driven serial communication, a command interpreter and driver for LEDs and buttons from my toolbox. Very handy!) To really benefit from this, you need at least two debug/programming tools and development software (IDE) that you can run multiple simultaneous copies.
*A really good PC with a 30" display (or two). You want to be able to have a datasheet, schematic, PCB, processor debug and some other windows open, all at once. The more pixels and screen estate you have for this, the better. I have no idea where the practical upper limit is. With a 30" I'm switching the top window all the time. Btw, you want SSD on that.