I think Panzerphill is spot on, this is condensation caused by running the engine for short periods and is normal under those circumstances and not an issue, as for the correct oil to use it is best to refer to the manual and use the oil most suited to the ambient temperature the bike is used in. As for oil brands and price, the grade of the oil is the important thing not necessarily the brand any reputable brand of the correct grade should suffice. And if possible change the filter at the same time there is no point filtering new oil through old dirt in your old filter. Hope this is of some help.
