If you like the look of the SXmini, but not the price, it may be worth looking at a
ZNA clone. Similar aesthetic, lower price tag. It's a chinese clone chip, though, so I'm not sure how well it performs, and you won't have a solid warranty backing it up like you would with a SX or DNA based device..
The big issue with trying to get one of these higher wattage devices at a low price point is that quality chips aren't cheap. An authentic DNA40 or SX350 chip alone costs $60-70, and then you need to put it into some sort of enclosure, add buttons and a battery holder, and wire it all up, so there's more parts and some labor on top of that. Then the guy (or company) who makes it needs to make some sort of profit, as does the vendor who buys it from them and sells it to you. Some of the less pretty box mods use the SX330 (the IPV series and Sigelei boxes), which is significantly lower cost (and still a high quality, authentic YiHi chip), but then you end up with the boxy look you don't want.
I'm not trying to be rude, so please don't take this the wrong way. But if you're happy with what you have and are just looking for the mod that's your vape nirvana, it might be worth considering continuing to use your Zmax while you save up a little bit for a more expensive device. I mean, it's the be all end all, right? It kind of sounds like you're only interested in something that would be considered a high end device, but not willing to pay a high end price tag for it. In vaping as in all other things, you usually get what you pay for. The disclaimer here is that you're talking to a guy who owns a Provari and an SXmini, so I'm obviously ok with paying $200 for a quality mod. And I feel like both of those purchases were worth every penny and then some. On the other hand, those are the only two mods I've purchased in the past year, while my coworker who likes cheaper mods went through 5 or 6 of them that went bad before he took my advice, got a Provari, and found what he was looking for. Overall, I've spent less than he has, I just did it in bigger chunks.
Side note - I haven't heard of anyone having problems with the YiHi chips hitting higher watts. Mine's dead accurate from 5 watts all the way to 60, and several other people have tested theirs with the same results. There's a reason the SX350 is the most popular modder's chip in the high wattage ranges.