A manual can be purchased from the manufacturer. Many local libraries have manuals available for televisions, DVD players and VCRs.
The best site for finding a manual for your item is Retrevo. See related link I posted.
You can do it, and you don't need a "combo" machine. Any VCR can be connected to a DVR to copy old tapes to DVDs. The quality won't be as good as an original DVD, because the videotape is an analog recording and has to go through A-D conversion before it can be recorded on a DVD.
Sylvania makes the DV220SL8 DVD/VCR Combo
Sony DVD/VCR Combo Player, SLVD370P
While they make DVD/VCR combos that will play DVD-R and DVD-RW, there does not appear to be a DVD/VCR combo with a DVD writer available for purchase.
The Sylvania DV220SL8 DVD/VCR Combo is under $80
Refer to your owner's manual. It's all in there.
Toshiba tends to offer the cheapest DVD/VCR combo, starting around $95 new.
Yes, Sony makes several versions of a DVD/VCR combo. These include progressive-scan DVD/VCR combos and DVD recorder/VCR combos. The latter is capable of copying VHS content onto DVD.
There are a lot of DVD/VCR combo units that are top of the line and here is the JVC HR-XVC20U Hi-Fi DVD-VCR. This might be what you're looking for.
You'll find all that in the owner's manual.
Panasonic makes great DVD/VCR combo players that will integrate well with your home theater.
Any of the DVD/VCR combo players that say DVD-RW will be able to record both.