What size room? A lot depends on that
Listening arrangement to reveal imaging?
ON or IN bookcase, or just small on stands? You want to have your tweeters aimed at seated ear height.
Efficient or high efficiency speakers will help keep the integrated amp's power amount low, thus small: size, heat, weight, cost, and more options regarding placement. Small space: less heat is always good.
I have that Carver, amazing, for what it does, fits anywhere, but I would not recommend it for it's sound qualities, it has no features, no volume or balance, spring clips for speaker wires, thus even for a single source, you need a preamp, thus space needed for 2 pieces.
Staying small, wanting tubes, I just replaced my Carver with a wonderful sounding compact Luxman Tube Integrated, fits in or on top of a bookcase. SQ-N150. Has both MM and MC phono built in, keeps you down to one component. (limits: only 10 wpc, no pre-out/main in).
http://www.luxman.com/product/detail.php?id=33I go out to a single self-powered sub for low bass extension, not 'real' low bass. Then to 'real' bookcase speakers (fit inside the shelf depth with no port or front port only).
It would be better to have an integrated with pre-out to self-powered sub, sub back to integrated main-in (or a tape or processor loop). That method reduces amp's need to make low bass, and small mains don't try and make low bass, which helps small speakers with no ports; helps you use less efficient small mains, allows a much lower powered amp.
Raven says low bass is about 65% of power needs, scroll down a bit here
https://www.ravenaudio.com/product/nighthawk-mk3-tube-amplifier/Despite the advice about efficient speakers, I am getting away with using the least efficient speakers I ever owned (Wharfedale Diamond 225, 87 db) with the lowest powered amp (10 wpc), and a self-powered sub, 12", 800 watts in my small office.
btw, before I brought it up here, I hooked the little Luxman 10 wpc to my very efficient horns/15" woofers in the main system. It sounded great, good volume for my typical needs, but not enough when I want to blast bass heavy content.