Hi Jem, welcome
Are you an offical member? As in you have access to te website so you can find syn values? If you are, I think your best bet would be to search on there for you favourite things and see what the syns values are. If I had the time I could try to sit here and list all the branded foods that are low synned, but I can bet that at least half of the things I might list may ont be of any interest to you!
Off the top of my head the only thing I can think of is that some of the Batchelors Pasta n Sauce's are free (cheese & brocolli, chicken & mushroom) but that is providing they are made without the butter and milk.
The other suggestion I've got for you is if you are attending group, there are 3 books which are massively useful - the low syn snacks book at £1.95, the free foods book at £1.95 and then the food directory, which I think is £7.50. The two books at £1.95 are only slim books, and ideal for stashing in your handbag for times when you're on the move and need some low synned ideas