Andrew,
Ilford Multigrade paper does not respond very well to selenium toner although results with other toners are very good. Ilford Warmtone was designed to respond well with all toners and is worth a try. Other papers worth experimenting with are Oriental Seagull, Forte, Bergger, Agfa, Kentmere (if you are in the UK) Luminos in the US, I understand that they are more or less the same papers with different names. These are the main papers available although I'm sure that other APUG subscribers will add to this list.
My personal favourite papers for selenium and gold toning are Ilford Warmtone, Oriental Seagull, two papers that I have used for many years and more recently, Bergger who have started making papers in the past 7 or 8 years.
Generally, papers are made with different characteristics, either warm, neutral or cool toned and all respond differently to toning. The normal colour of each are, warm tending toward brown, neutral cooler brown toward blue, cool will tend to be noticeably blue when compared to the others. To add to the complexity of the issue, papers by different manufacturers will differ in colour and respond differently. You also need to consider the changes that different developer combinations will have on the paper colour even before you start to tone. I don't wish to confuse you with all this information but feel that you should be aware of them and please don't be put off by it. You are about to enter an exciting phase in your journey of discovery in photography.
Might I suggest that when you do try toning new papers that you keep a note pad with you in the darkroom and make a note of dilutions, temperatures and time toned. If you need more detailed information don't hesitate to contact me off line and I'll be happy to help.
Good luck and enjoy the journey.