Cheap and powerful pre/power combo $1k budget

Most amplifiers support 4 ohm speakers just fine. If you want to be sure, find the specs for your amp. There are no switches to set.

The lower the ohms, the more power the speakers will pull from the amplifier at any given time.

Ohms (a measure of "impedance") are a pretty approximate thing. An 8-ohm speaker can act like a 4-ohm or even a 2-ohm load depending on the music being played, and will vary during a song. So amplifiers are for the most part used to dealing with varying impedance.

Look at a used Odyssey Stratos Plus (around $650-750 depending on how old), and a moderate level tube preamp used.
You should be around $1000.
Good Luck.

Thx for suggestion, and more suggestion would be nice.
One more stupid question, my speaker only allow 4 Ohms input. However the amp said: "power levels in excess of 200 watts per channel into 8 Ohms." and it does not come with 8 Ohms to 4 Ohms swithch or 4 Ohms output, can I still connect my speaker to 8 Ohms output from my amp? Does it affect the sound quailty?
thx

Older Sunfire if you want a pre-amp and amp, tons of power. (Theater Grand I and Cinema Grand)

Sometimes you can find a Plinius integrated in your price range. 8100 is in your price range.

Rotel RB-990BX 200w amp w/Rotel RC-995 Pre-amp. Around $800 used. Leaves enough for an excellent Interconnect. Lots of other fine choices as well. Good Luck!

Parasound P3 pre amp with Parasound A23 power amp might be just about what you are looking for. 125 wpc. So not as much power as you had asked for, but close.

This is a fantastic combo for just around 1000 dollars used.. Even has balanced inputs, and gain controls on the amplifier. It's from the halo line of parasound so all units have sweet looking blue lights as well.