If I might add a couple of comments to Robert's expert advice:
If your brother is your only living male to test your father's surname then it is handy to know that (last I heard) Family Tree DNA stores the yDNA sample for 25 years if it is not used up before then and I have not heard of any other company that offers that as a part of initial testing.(I don't keep up with this so you would want to verify.)
If there is a chance you would not own or inherit the yDNA test results sample thenyou should max out every yDNA test that FTDNA has available at this time.Go for the 111 marker yDNA test and you might as well go ahead and do that asap if it was your choice as 111 test has never been on sale except for the initial 68-111.(If your brother's nursing home stay is permanent why would you want to wait for the test?)Also, do the haplogroup test and any advanced SNP test that your project admin or expert adviser suggests would further add to your ability to match with other folks in the data base.There is a place on the FTDNA personal page to assign a beneficiary of the yDNA test results if your brother is still responsible.
If you lost control of his account and the results were taken down from the public FTDNA site you would at least still have the results in your records and you can't replace that IF he is your only known source for that yDNA.