Is your battery so knackered that you need to keep it charging all day, every day?
I've left my bike for up to 2 weeks at a time just chained up outside (while on holiday), came back, turned the key and off it went... The battery is now about 3 years old, is an Odyssey one, and I've never had to charge it at all, trickle or otherwise - the bike lives outside all year, come rain/shine/snow/whatever. The majority of my journeys are pottering around to town / to do work quotes and the like, under 10 miles radius and then a few longer rides thrown in now and again.
Even when my alternator drive failed and the bike died as I pulled up at home, it just sat for a few weeks while I waited for parts and got it back together - still had enough oomph to start it up without charging again.
But hey, if you're really set on one - I've not seen a solar battery 'conditioner' - imo a solar panel of a sensible size wouldn't provide enough power to actually condition a battery anyway. All the solar trickle chargers are just that, a panel with a voltage control module - the current will vary with available light and will cut off completely when it gets dark enough for the voltage to drop. Even if you find one marketed as a 'conditioner', good luck getting one that does what it says on the box.