The Onkyo 618 would be the obvious replacement. What is your budget?
Other equivalent models would be Sony 1030, Denon 2113/2313 and Yamaha 673/773. What is your budget?
You could get your 608 repaired fro around £100.
Maybe £300-£500 depending on the features. I'll have a look at those models.
I hadn't considered the Onkyo repair, as this episode has alienated me from the brand (apparently the HDMI thing is a common problem). Also, I don't want to wait 6 months for Onkyo to repair it, unless you know of a reputable place for such repairs?
Get hold of Genserve as they are the Onkyo official repairer. My brother had his fixed and only took a week or so. Give them a call for a quote and estimated time for repair. If you are OK with a soldering iron then you could repair it yourself for a few pounds. There is a guide on youtube that can show you what to do and what to replace.