Having worked with the mentally challenged, I can assure you that non-monetary gifts are as welcome to them as they are to anyone else!
While I'm sure your intentions are altruistic, let the guests bring what they wish. Of course, if you know of something specific your brother wants, such as a particular article of clothing, toy, video game, DVD, etc, just assign such to each guest before the event.
Keep in mind that most theme parks are expensive, as is the cost of travel, hotels, car rentals, etc, so your guests might resent your asking for money or making specific suggestions.
While I'm sure your intentions are altruistic, let the guests bring what they wish. Of course, if you know of something specific your brother wants, such as a particular article of clothing, toy, video game, DVD, etc, just assign such to each guest before the event.
Keep in mind that most theme parks are expensive, as is the cost of travel, hotels, car rentals, etc, so your guests might resent your asking for money or making specific suggestions.
