Much is dependent on industry and customer type, so it's hard to give specific advice.
In my experience PayPal standard works to a degree, however like it or not some customers will not recognise they can use a credit or debit card, despite what is said and written, so this may loose a few sales, again depends on customer profile and type.
Using PayPal Pro will get you a virtual terminal which is invaluable if you want to seal a sale over the phone and costs £20 a month from memory, you can then also build this into taking the payment on your site, how easy this is depends on your site design and ability.
Longer term I would recommend a merchant account, this will then be very clear to customers that credit and debit cards can be used, it will be what they are familiar with, and you can then just run standard PayPal alongside for those who prefer to use that, you will not need PayPal Pro as the merchant will give you a virtual terminal and your charges will be less.
Regarding bank transfers you can of course publish details online, but in my experience the customer is likely to contact you first via email or phone to let you know they would like to pay that way.