You deffo need bibshorts that fit properly - tackle support is essential as is protection of your perenium. There are some really bad shorts out there - my current favorites are etxeondo or
probike kit louviers heritage (just ordered another pair this morning - majorca is looming) they punch well above their weight at £40 they are half the price of equivalent shorts like castelli. probike kit have just stopped doing the heritage shorts but the etx's are widely available. Santini are ok and there is always the premium brands like assos/rapha if your pockets are deep enough...certainly really good pro quality shorts. Castelli and sportful are also great quality shorts.You would be better going to a decent shop and trying some on - fit is really important.
Dont forget you need to be commando as well. No point having seams digging in on your sit bones.
I have about 10 pairs in my bike kit box and the porobike kit ones come out first, then the etx's. Have a look at Prendas website or probike kit. Sportpersuit have some northwave/others on at the moment.
Ribble is always another good bet.....fit is important though.