I really don't think he will be happy with a bass amp for guitar. The speaker will have a bss cone for sure and while that can be cool coupled with a guitar-voiced amp with small coupling caps and guitr-centric tone control center frequencies, it'll be way boomy (pun intended) for guitar when coupled with a circuit voiced for bass. Hes going to wind up running the bass at 0 all the time (though if he gets a gig playing bass hes set). If hes going to go LOUD solid state in a small package with a master the blackstar ID amps or Roland Blues Cubes will serve a guitarist better for practice and light stage use. And they are pretty darned light 1x12s. I also recommended the old Marshall Lead12 to him. Great little solid state practice/small gig amp... if Narcist were primarlily a bassist the Rumble would eb a cool amp for practice and some gigging that could serve as a guitar amp in a pinch, but as hes primarily (as of now EXLUSIVELY) a guitarist, a bass amp will not make a lot of sense since hes not even going to use it as intended.
in 5 watt tube amps the big cotnenders are the blackstar, the ac4tv, the marshall class 5 and the VHT 5 watter (is it a custom 6 or something? I forget, but its a good value).... ya gotta decide if you need a lot of features or just a good core tone, if you want an EL84 or a 6V6 and then decide if you need it to be handwired.... the VHT with a 6V6 is pretty cheap, is hand-wired on a nice turret board for easy service and gives a nice,bare-bones tweed Princeton type circuit for not a lot of scratch.... a used ac4tv might be even cheaper, but its more british sounding obviously and its made on a PCB... the mashall uses a 6V6 I think but sounds more british than a champ and is a lot darker than the vox (also PCB construction but not nearly as affordable as the AC4TV and for my bucks is a muddy sounding amp comparatively).... then there's the blackstar stuff that is generally higher gain and voiced on the modern-side of things, lots of features to putter with, PCB construction, but I am not familiar with all f their models, the 5 watter included.... I got really turned off to their affordable amps after trying some venue series heads. Not my bad though they will suit many people in the high-gain crowd. Maybe someone know more about that HT-5 than me and can chime in.... I just don't like most of blackstar's offerings other than the artisan stuff that's basically boutique or vintage clones. They're like England's Mesa. Too many options. In brit high gain I find the orange stuff to be cooler, Ade Emseley is really decisive about voicing the amps and oesn't clutter tham with switches and extraneous controls..... but I digress. Maybe someone can describe the HT-5 for our young friend??? OH! There's also the Laney Lionheart 5 watter that sounds fantastic and is a lot like the AC4HW but with Laney's voicing and a switchable extra gain stage that actualy sounds really good... its a got a lot of knobs and switches for a handwired 5 watter though. However, the Laney sounds more like a Marshall to me than the Marshall Class 5, can get voxy set clean, and its made better (a rarity for Laney, usually they are like chintzy plexi, 800 or vox clones). My buddy has a Lionheart 5, I always liked it and still like it.
I like simple amps whether they are big or small... 1 to 3 knobs is a good way to go, there's less between your hands and the speaker! and in the case of PCB amps, the simpler the design the better the reliability (and tone! less traces means more space between the traces and therefore less crosstalk and stray capacitance mucking up your sound)
that's the Jim .02