Yes, entirely possible. Solar panels are just a simple negative and positive (2 wire) connection. Newer panels will be cheaper and perform better. You can easily splice and seal up the job with quality heat shrink type connectors I would think. I've done it a time or two. It's typically 10 gauge wire used which will carry up to 30 amps and you're nowhere near that in the 225 watt range. You will need to find out how yours are wired, series or parallel, and wire the new ones the same way. It should be fairly self explanatory when you look under them up top.
I would think your biggest challenge would be either matching the physical size of the panels for ease of installation or just build a new rack.
I have exclusively used the 100 watt Renogy or similar panels for the cheap price and if you go that route you could easily upgrade to 300 watts (3 panels) for $350 or so. If you have a marina or any shop do it I would expect you'd pay a lot more.
If you have more in depth technical questions I would definitely recommend PMing Scalf77 (Greg). He really knows his stuff.
Good luck!