Ahh cool thanks a bunch man, yeh luckily I do still have my DS Lite with the GBA slot and a copy of Soul Silver, so I think I just need to finish fighting Red and I'll be able to transfer them, cheers for taking your time to answer my question!
Actually, you don't have to beat Red to transfer Pokemon from a 3rd Gen game. You can do it just after getting the National Dex in HG/SS (or D/P/Pt, if you see all Sinnoh Dex Pokemon). Just further clarifying this.