Do you think there would be a problem matching up a Trace Elliot ELF with a Phil Jones C27 cab?
I absolutely love Phil Jones Bass gear. Right now, my main rig is an old Suitcase combo with 4B extension cab, but I've got tons of PJB stuff all the way down to Briefcases and Bass Cubs. They put out a very well balanced, Hi-Fi sort of tone with tightly controlled bass ... but they sacrifice volume to get you there. They're also surprisingly quite heavy for their size, especially the ones with the (much richer sounding) Piranha drivers rather than the (darker and flatter) Neo drivers.
With a small, low-powered amp like the Trace-Elliot ELF you're just not going to get a huge, room-filling sound out of a single C27 cab. Realistically, you'll need to trade off some control over deep bass for more volume/projection. For a lightweight rig, I would go one of two ways (both from personal experience):
(1) Gallien-Kreuger 112MBX. They're only $325 brand new, so even a pair won't break the bank. Very, very light (only 16 pounds!) and the form factor makes them super easy to transport. They have an exaggerated mid-range honk, which makes them seem quite punchy and loud. Very nice for rock/blues with a PBass.
(2) Markbass New York 121. This is about twice the price and twice the weight of the 112MBX, but can handle a lot more power. Still pretty boxy in the mids, but it adds more deep lows. Unlike PJB, there's a loose/wooly quality to the lows ... but they're very much present. That "woofly" tone makes the cab sound almost like an Ampeg flip-top.
I actually prefer the cutting midrange bark of the 112MBX. It really cuts through the mix and sounds great to my ears. With a budget of $600 you're looking at a pair of G-K cabs
vs. a single Markbass. Any modern Class D micro head sat on top of a 112MBX stack would make for an awesome gig-ready package.