Not everyone is of the same opinion as me, but I would suggest exercising caution in proceeding with ANY kind of swinging activity without your wife. That includes going to "just watch". Carol is right; single guys have a tough time trying to find couples who will play with them, and those who do tend to want the whole bowl of wax. Add to this that you aren't actually single. That you would be participating not only without your wife, but possibly (probably) without her consent. And from the way you described your situation, I get the feeling that even if she did grant you her consent, she wouldn't be happy about it. Unhappy wife=bad situation. If it were us, we wouldn't feel right about that. It wouldn't matter if you were a dead ringer for Brad Pitt, we would still decline. Sorry for the wet blanket.
Best suggestion: focus on enhancing your wife's sex life, not yours. Swinging isn't the only way to supercharge one's sex life. She's probably feeling a little alienated and inadequate due to your intense interest in swinging. Most women who do not understand what it is about allow themselves to feel these kinds of negative things, and feel that your interest in it is a direct blow to their self-esteem and sense of self-worth. After all, why else would you feel the need to screw other people unless she wasn't enough for you? This is what she is thinking. Better decide if her fears are justified or not, and let her know either way. You'll want to find ways to reassure her about how you feel about her, what vision you have for your marriage to her, and exactly what swinging means to you.
BTW, if you're thinking that swinging is about more sex (with other people) or better sex (with other people), you're going to be disappointed. I'd say on average, regularly active couples might get together with other swingers about once a month. Maybe less. It's the way that it affects your relationship with your spouse that counts.
Lotsa words here. Sorry for the longish post. Welcome to the board!