Look at the Yaesu FT-60r (~$190) among other models/brands, water resistant (not submersible though), dual band, ROBUST, excellent belt clip, can use a 6 AA cell battery pack (NiMH or alkaline) w/ FULL output power, uses an SMA antenna connector, BUT uses a single 4 conductor 3.5mm phone jack/plug vs a pair of phone jacks/plugs for speaker/mic & data connection -- not a big deal as accessories for Yaesu/Vertex are readily available as are Y adapters to dual jack configuration. Yaesu and others have other more expensive dual banders, but unless a specific feature (e.g. IP67 watertight/submersible) is required the FT-60r is tough to beat.

If possible, touch and hold before you buy, as ergonomics, display readability, etc. are important in an HT. Beware of poor battery life w/ alkaline cells at high power, but conversely, note that NiMH's have high self discharge rates in storage.

All HT's will be either SMA or BNC connectors for antenna, if needed, either can be adapted to the other or either adapted to a female UHF via a short (1-3') small coax cable adaptor, but if a remote antenna is to be used as primary antenna, a mobile rig is a better choice. speaker/mic connectors vary, but after market accessories are readily available for all brands/models.

I'm not convinced there's a lot of money to be saved buying HT's used (mobile rigs, at least single band/2m, maybe; HF rigs, sure) but keep an eye out anyway.