They will both need to be taken out of the bags before going through security. As for customs, I don't know, it may depend on whether they are new or used, and how they maybe perceived as imports? If you are returning home with them and can proved that, you should be ok.
An you don't think that eradicating AIDS is a good enough cause? Actually The Gates Foundation are doing much more than that, they are also helping to eradicate Polio in the last 4 endemic countries of India, Pakistan, Afghanistan & Nigeria.
Not for T5 lounges, they are all operated by British Airways, and you will need to be an executive club member or have a business or first class ticket to gain access.