I highly recommend the Costco unit.
I purchased the 1000w inverter a couple years ago and installed it under the
drivers seat and wired it directly to the 2nd battery with a cut over to the
main batt so I can draw from one or both. The 1000w unit has worked
flawlessly and will even start my 5350 btu window AC unit. I bought it in
the Costco store for $69.
It looks like they only have the 1750w unit now by way of their website. I
will likely sell the 1000w unit for the 1750w down the road.

Costco price $199
Specifications:

  a.. Maximum continuous power: 1500 watts
  b.. 5 minutes continuous power: 1750 watts
  c.. Peak surge capacity: 3000 watts
  d.. Recommended for use with a stand alone deep-cycle RV, marine or
golf-cart battery
  e.. Dimensions: 9.4" W x 17.3" L x 3.2" H
  f.. Weight: 9.4 lbs.
  g.. Warranty: one-year
LINK

http://tinyurl.com/b7mcy

----- Original Message -----
From: "Christopher Gronski" <gronski@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, December 01, 2005 3:53 PM
Subject: Re: Inverter at Radio Shack

> While I tend to agree that bigger is better, my 300 watt Radio Shack
> inverter (12Vdc 30A MAX, output 115Vac) has no problem powering my
> laptop (16V Input: 100V-240V~ 1.1A 50-60Hz, Output: 16V 2.7A). I
> recently used it on a 20 hour round trip drive to Rhode Island.
>
> Chris
>
> On 12/1/05, Robert Rountree <syncro87@hotmail.com> wrote:
> > I second or 3rd this... I have a 175 watt and a 300 watt inverter... the
300
> > can NOT run my laptop... it will charge it (takes a good while) But it
will
> > NOT run and charge it at the same time..... 3 mins into running the fans
> > kicks in ..less than 5 mins the alarm goes off and it shuts down. The
175
> > watt one, with no fan would run my old laptop for hours. The New one...
will
> > NOT run my new bigger laptop .. The power brick says ... 120 watts ...
go
> > figure?.. my .02 worth... get a min 750watt inverter... if you're doing
> > anything more than charging your cell phone or small camera batterys.
> >
> > >>Date:    Thu, 1 Dec 2005 15:43:33 +0000
> > >From:    Dave Vickery <davevickery@HOTMAIL.COM>
> > >Subject: Re: Inverter at Radio Shack
> >
> > >>WalMart Sells Black & Decker 750 Watt (peak 1500) for 49.99.  300
Watts is
> > not enough.
> >