For these requirements, there are many models which should fit the bill. Getting the tones correct and not blocking up shadows and burning out highlights is the major headache. This is a function of having an ICC calibrated monitor and using the scanner software well. Avoid the "auto" settings, they will soon undo your hard work in the darkroom!
Third party scannner software is available that operates a wide range of scanners. Vuescan at www.hamrick.com is great value with unlimited upgrades and can increase effective scanner performance, especially the multi-pass feature to reduce noise in shadows. It is not everybody's cup of tea requiring numbers in boxes,but you can calibrate and save settings which is a huge help. You can also transfer it when you change scanner.
Silverfast (at www.silverfast.com) is more expensive but graphically led. Personally I struggled to get to grips achieving consistency with Silverfast. Despite having studied the 370 page manual!
Hope that this assists your entry to the digital minefield.
Bax