advice on s3 sytem upgrade

Hi guys. I know this has been discussed Many times hut im after a bit of advice about my s3 sound system. Firstly my s3 has no bose but the symphony head unit. So i want to know what head unit people would buy for around £150. And i already have a 10 inch db audio sub. Directed 250d 2 ch amp and a kenwood 4 ch 600 w amp. Was wondering what people would do with these. Do i use the 4ch amp to run front components and sub or use the directed amp on a sub and 4ch amp to run front and rear speakers. Im going to get this all installed so i could do with know what to get fitted. Any help would be great guys thaks

The ice section on the forum is usually slow. I thought this would go unanswered. Its only because i have half of the equiptment im unsure of what route to take. Hopefully someone will add sometuing

I have no idea andy i will try find out. But doing what you have said sounds an easier option. As for speakers i want a good upgrade without killing the bank. Ill obviously need your speaker brackets for this. How much do they help? Tbh my old s3 had bose and that was good enough for me. This system is aweful though. Thanks for help so far top man on this subject. Daz