The Sparc 5 has a 13W3 connection, yes ?
Well there are 13W3 to SVGA converters available from Sun amongst others priced about $50.
BUT (and it's a big BUT), the monitor that you are going to try and use has to use a particular sync mode. I'm really sorry, but it's a couple of years since I did this, so I can't remember whether it's sync on green or composite sync.
There are of course highly expensive boxes out there that will do the conversion too.
Short answer is that it can be done, but do your homework on your monitor first. Ian
"IF" is not a word it's a way of life