Remember the rig is only the operator interface, but it doesn't do the work of making contacts. Your antenna, as the station to ionospheric interface, does that.
There are lots of great rigs on the market, both new and used, and I'd suggest you try some out at a local radio store if you can, to get a feel for what's available and to your liking. The IC706MkIIG is a fine little rig with an excellent performance-to-cost ratio, but it's not for me -- tried it, thought it worked well, but I'd have a difficult time actually using it daily...too many menu functions, and lacking in panel adjustments for things I constantly adjust (like CW keyer speed, which I adjust probably 100 times a day); thus, although it might be perfect for some, it's not for me, at all. That's why I recommend trying rigs for a "test drive," if at all possible.
However, if you have a ham radio budget, and most of us do, I'd always recommend allocating "most" of that budget to antennas. Given a budget of $2000 to get "back on the air" on HF, I'd assuredly allocate $1500 to antennas and supports (maybe a good used tower and rotor, a good beam, new coax & rotor cables, etc), and maybe $500 on the rig. Or, possibly $1750 on the antenna system and $250 on the rig. Remember what really does the work...also, it's really easy to trade in, swap, and exchange equipment. Antenna work takes much more effort and planning, and you probably don't want to be erecting, dismantling, and re-erecting antennas every few months.
73 de Steve WB2WIK/6